Manual retracting box step for pick-up trucks

ABSTRACT

The step assembly ( 20 ) includes a mounting bracket ( 26 ) mounted to an under-carriage of the pick-up truck. A step (30) is pivotally secured to the mounting bracket. The step can rotate between a stowed position with the step disposed adjacent the mounting bracket and an operative position with the step extending from the bracket. A coil spring is mounted between the bracket and the step for continuously biasing the step toward the stowed position. A ratchet mechanism, having a pawl, a cam and an over-center spring, is mounted between the bracket and the step. The ratchet mechanism locks the step in the operative position in response to rotation of the step from the stowed position to the operative position. When in the operative position, a user can stand on the step assembly to access the bed of the pick-up truck. The ratchet mechanism also unlocks the step in response to over rotation of the step beyond the operative position. Once unlocked, the step automatically counter rotates back to the stowed position. When in the stowed position, the step assembly is concealed underneath the pick-up truck.

This application is a 371 of PCT/CA00/00548 filed May 10, 2000 whichclaims benefit of provisional No. 60/133,282 filed May 10, 1999.

FIELD OF INVENTION

The subject invention relates to a box step assembly for a pick-up truckfor enabling a user to easily access an interior of a pick-up truck bed.

BACKGROUND OF THE INVENTION

In recent years, the popularity of pick-up trucks has risentremendously. The rear area of the truck bed is accessible through thetail gate. However if the rear area blocks access to the forward area,access is only available by going over the side wall of the truck bed.The truck bed is usually elevated because of the high ground clearanceof these vehicles. As a result, it is very difficult to climb over theside wall.

Step structures have been used to assist passengers in entering andexiting pick-up trucks. On recent models of the Ford F-150 pick-uptruck, a step is integrated with the outer side panel of the bed andpositioned forwardly of the wheel well. The styling considerationsrestrict the depth and size of the step, presenting only a smallstepping surface.

The patent literature has proposed various retractable vehicle stepstructures in order to resolve some of the problems associated withconventional step structures. For example, U.S. Pat. No. 5,716,064proposes to provide a step that mounts to the forward suspension mountof the pick-up truck. The step is telescopically connected to themounting bracket. The user pulls the step out for use and then pushesthe step in when not in use and thereby conceal the step under thetruck. This type of step detracts from the ground clearance of thetruck. Further, this type of step is still visible when in the retractedand stored condition.

Other examples of prior art steps include U.S. Pat. Nos. 4,108,458 and5,513,866.

The prior art solutions, however, have a number of deficiencies. Onesuch deficiency is that many of these steps detract from the groundclearance of the vehicle. In addition, these steps are still visible,when in the retracted and stored position. Further, many of the manualstep structures have no devices to assist in the movement between thestored and deployed positions such that the steps may become difficultto operate.

Accordingly it would be desirable to develop a step assembly which doesnot detract from the ground clearance of the vehicle, cannot be visiblewhen in the stowed position, is easy to use and retract, and has anadequate stepping surface.

SUMMARY OF THE INVENTION

The disadvantages of the prior art are overcome by the subject inventionwhich includes a step assembly for use with a pick-up truck typevehicle. The step assembly includes a mounting bracket mounted to anunder-carriage of the vehicle. A step is pivotally secured to themounting bracket. The step can rotate between a stowed position and anoperative position with the step extending from the bracket and thevehicle. A coil spring is mounted between the bracket and the step forcontinuously biasing the step toward the stowed position. A ratchetmechanism, having a pawl, a cam and an over-center spring, is mountedbetween the bracket and the step. The ratchet mechanism locks the stepin the operative position in response to rotation of the step from thestowed position to the operative position. When in the operativeposition, a user can stand on the step assembly to access the bed of thepick-up truck. The ratchet mechanism also unlocks the step in responseto over rotation of the step beyond the operative position. Onceunlocked, the step automatically counter rotates back to the stowedposition.

Preferably, the step assembly is configured to retract behind the outerbody panel such that the ground clearance is not impeded and themajority of the step is not visible when in the stowed position. Thesubject step assembly is easy to operate from and to the stowedposition. Finally, the step has a relatively large stepping surface forthe user.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the present invention will be readily appreciated asthe same becomes better understood by reference to the followingdetailed description when considered in connection with the accompanyingdrawings wherein:

FIG. 1 is a perspective view of the present invention with the stepassembly shown in a stowed position;

FIG. 2 is an exploded perspective view of a mounting bracket of the stepassembly of FIG. 1;

FIG. 3 is a side elevational view of a handle for the step assembly ofFIG. 1;

FIG. 4 is a perspective view of a mounting lobe for the handle of FIG.3;

FIG. 5 is a perspective view of an underside of the step assembly of thepresent invention;

FIG. 6 is an exploded perspective view of the step assembly of FIG. 5;

FIG. 7 is a cross-sectional view taken of the step assembly of FIG. 5;

FIG. 8 is a perspective view of the step assembly of FIG. 5 shown in thestowed position;

FIG. 9 is a perspective view of the step assembly of FIG. 5 shown in apartially deployed position;

FIG. 10 is a perspective view of the step assembly of FIG. 5 shown in afully deployed and operative position;

FIG. 11 is a perspective view of the step assembly of FIG. 5 in anover-rotated or releasing position;

FIG. 12 is a side view of a ratchet mechanism of the step assembly ofFIG. 5 shown in the stowed position;

FIG. 13 is a side view of the ratchet mechanism of the step assembly ofFIG. 5 shown in the deployed position;

FIG. 14 is a side view of the ratchet mechanism of the step assembly ofFIG. 5 shown initially being released and rotating in a first directionwith a cam engaging a pawl to pivot the pawl to a second position;

FIG. 15 is a side view of the ratchet mechanism of the step assembly ofFIG. 5 shown when the step assembly is rotating in the first directionwith the pawl being pivoted to the second position;

FIG. 16 is a side view of the ratchet mechanism of the step assembly ofFIG. 5 shown when the step assembly is in the fully released position;

FIG. 17 is a side view of the ratchet mechanism of the step assembly ofFIG. 5 shown when the step assembly is being returned to a stowedposition;

FIG. 18 is a side view of the ratchet mechanism of the step assembly ofFIG. 5 shown when the step assembly is continuing to be returned to thestowed position and is rotating in the second direction with the pawlbeing pivoted to the first position; and

FIG. 19 is a side view of the ratchet mechanism of the step assembly ofFIG. 5 shown when the step assembly has returned to the stowed positionas also shown in FIG. 12.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the Figures, wherein like numerals indicate like orcorresponding parts throughout the several views, a box step assemblyfor use with a vehicle 22 is generally shown at 20 in FIG. 1.

The box step assembly 20 is preferably used with a pick-up truck typevehicle 22 having side walls 21 defining a bed box 23 as illustrated.The step assembly 20 is shown mounted to the pick-up truck forward of arear wheel well 24. It is appreciated, however, that the subject stepassembly 20 may be used on any suitable type of vehicle at any desiredlocation.

The box step assembly 20 includes a mounting bracket 26 which is adaptedto be mounted to an under-carriage of the vehicle 22 by bolts or othersuitable fasteners, such as rivets or fastening methods, such aswelding.

Referring to FIG. 2, the mounting bracket 26 is shown in greater detail.The mounting bracket 26 has a generally triangular or wedge shapedframe. The wedged shaped frame is preferably formed of sheet steel andhas apertures on the surfaces thereof to reduce the weight of thebracket 26. A hollow tube 28 is preferably welded onto the bracket 26 atthe forward apex of thereof. Flanges 27 extend from the bracket 26 topresent a mounting surface. A secondary bracket (not shown) may bemounted to a mounting end of the bracket 26 to configure the mountingbracket 26 for various vehicles. Hence, the mounting bracket 26 of thesubject invention is designed for utilization on virtually any vehicle.

Referring to FIG. 5, a step 30 is pivotally secured to the mountingbracket 26 for rotation between a stowed position (as shown in FIG. 1)with the step 30 disposed adjacent the mounting bracket 26 and anoperative or deployed position with the step 30 extending from thebracket 26. The step 30 preferably includes a pair of arcuate orJ-shaped arms 32 pivotally mounted at the tip of the “J” to the tube 28.The arms 32 are preferably stamped from sheet steel and can be made inleft and right hand versions. Alternatively, arms 32 may be made withouta hand for universal application.

Referring to FIG. 6, the step 30 has deck or platform 42 for providing asubstantial stepping surface for the user. Each of the arms 32 has aflange 44 for interconnecting the platform 42 to the arms 32. The flangeportions 44 may be integral (as shown) or may be separate sectionsbolted, welded, or otherwise affixed to the arms 32. The platform 42 maybe formed of an integral plastic material (as shown) or may be a metalwaffle board and a protective cover (not shown). Platform 42 is fastenedto the arms 32 in a conventional manner, such as rivets, nuts and bolts,etc.

A handle 34 is pivotally mounted to the step 30. The handle 34 has agripping portion connecting with a main shaft 37. A pivot shaft 36extends from an end of the main shaft 37. A handle spring 38 is woundabout the pivot shaft 36. A mounting cam 40 is secured to an end of thepivot shaft 36. Mounting cam 40 has two opposed lobes.

Handle is pivotally mounted to one of the arms 32. Spring 38 extendsbetween the handle 34 and the step to continuously bias the handle 34toward a retracted position. Mounting cam 40 secures the handle to theone arm 32. Cam 40 will engage the inner flange of the arm 32 to limitthe travel of the handle 34 between the retracted position and theextended position. The handle 34 extends in a direction opposite thestep 30 when the handle is in the retracted position (FIGS. 8 and 10)and extends in a same general direction as the step 30 when the handle34 is in the extended position. When the step 30 is in the stowedposition, the handle 34 will normally be in the retracted position.However, the handle 34 will be positioned to be presented to the userand within easy reach under the vehicle 22.

A bumper 46 is mounted to an inside face of each of the arms 32 belowthe platform 42 for limiting travel of the step 30 to the stowedposition. Bumpers 46 also cushion the impact of the step 30 when itcontacts the bracket 26.

Referring to FIG. 7, a shaft 48 is journal mounted to the tube 28 forrotation internally of the tube 28. Bushings 50 are disposed between theshaft 48 and the tube 28 to rotatably journal the shaft 48 to the tube28.

The arms 32 are connected to each end of the shaft 48 such that theshaft 48 and arms 32 rotate as a single unit. The left arm 32, as viewedin FIG. 11, is welded to the shaft 48. The right arm 32 slides over theshaft 48 and is secured in place by a bolt 51. In addition, the shaft 48preferably has an irregular circumferential configuration, such ashexagonal, which engages corresponding irregular punched apertures 52 inthe arms 32. Preferably, the apertures 52 are punched at a tip of theJ-shaped arms 32. The irregular configurations fully interlock the shaft48 to the arms 32 for rotation as a single unit.

A spring 54 is mounted between the bracket 26 and the step 30 forcontinuously biasing the step 30 toward the stowed position The spring54 is preferably wound about the shaft 48 with a first end mounted tothe tube 28 and a second end mounted to the shaft 48 such that the shaft48 is continuously biased to rotate the step 30 towards the stowedposition. A pin 56 is inserted into the tube 28 to retain the first endof the spring 54. A second end is inserted into an aperture 57 isbushing 50. As appreciated, the biasing device 54 may be any suitablemechanism provided the step 30 is biased or at least maintained in thestowed position. In particular, a gas strut could be adapted to providesuitable biasing.

A ratchet mechanism, generally shown at 58, is mounted between thebracket 26 and the step 30. Referring also to FIG. 12, the ratchetmechanism 58 includes a pawl 60 interengaging a cam 62 for locking andunlocking the step 30.

The cam 62 is secured to the step 30 to pivot with the rotation of thestep 30. Preferably, the cam 62 has a corresponding irregular opening64, e.g. hexagonal, to interlock with the shaft 48 such that the shaft48, cam 62, and arms 32 rotate as a unit. The cam 62 preferably has acircular configuration with a smooth annular outer surface 66 and first68 and second 70 notches formed therein. The first notch 68 is smallerthan the second notch 70. The cam 62 further includes an outwardlyextending tab 72 disposed between the notches 68, 70 for selectivelyengaging the pawl 60 during the rotation of the step 30. A curvedcamming surface 74 merges smoothly with the tab 72 and the second notch70.

The pawl 60 is pivotally mounted to the bracket 26 such that the cam 62rotates relative to the pawl 60. In particular, an inner mounting flange76 is fixedly secured to the tube 28 with the pawl 60 mounted to themounting flange 76. The pawl 60 preferably has a crescent configurationwith first 78 and second 80 abutment arms extending on opposites sidesof the pivot 82. The first 78 and second 80 abutment arms selectivelyengage the first 68 and second 70 notches, respectfully, duringselective rotation of the step 30.

An over-center spring 84 is mounted on the mounting flange 76 andengages the pawl 60 for biasing the pawl 60 to either one of twoconditions, namely a locking condition urging the pawl 60 intoengagement with the first notch 68 and an unlocking condition urging thepawl 60 into engagement with the second notch 70.

An exterior cover 86 is secured to the inner mounting flange 76 andencompasses the ratchet mechanism 58. The cover 86 is preferably moldedof plastic and is press fitted onto the flange 76. A seal supportbushing 88 is mounted to the shaft 48 between the cam 62 and right arm32. The exterior cover 86 terminates at the bushing 88. A seal 90 isdisposed about the bushing 88 to seal the exterior cover 86 from theenvironment.

The particular movements and components of the entire step assembly 20are best illustrated in FIGS. 8 through 11. FIG. 8 shows the stepassembly 20 in the stowed position. FIG. 9 shows the step assembly 20 ina partially deployed position. FIG. 10 shown the step assembly 20 in thedeployed position. FIG. 10 shows the step assembly 20 in theover-rotated position

The user manipulates the handle 34 to move the step assembly 20 from thestowed position to the operative position. The user may also manipulatethe handle 34 to move the step assembly 20 from the deployed position tothe over-rotated position. Once the user releases the handle 34, thehandle 34 is automatically returned to the retraced position such asshown in FIGS. 8 and 10.

Referring also to FIG. 12, the working components of the step assembly20 as mounted to the bracket 26 which allow the step 30 to move, lockand release in the stowed, operative and deployed positions isillustrated.

The views of FIGS. 12 to 19 are taken from the right hand perspective ofthe step assembly 20. For illustrative purposes, the arm 32 is shown inphantom and is fragmented.

The coiled spring 54 biases the step 30 in the stowed position as shownin FIGS. 12, 1 and 7. The pawl 60 is urged toward the lock position bythe over-center spring 84 such that arm 78 follows the annular outersurface 66 of the cam 62. To move the step assembly 20 to the operativeposition, the user first pulls on the handle 34 from underneath thevehicle 22.

As the handle 34 is pulled, the arms 32 and cam 62 rotate relative tothe pawl 60 in the first direction which is shown at arrow A in FIG. 12.The cam 62 rotates relative to the pawl 60 until the first arm 78 dropsinto the first notch 68. Spring 84 will positively rotate the pawl 60into engagement with the cam 62. A click or ratchet sound will signifythe positive engagement. The first arm 78 will engage the cam 62 andwill prevent counter rotation of the step 30. In this position, the step30 will support the weight of the user stepping thereon. After the step30 has locked into this position, the user will release the handle 34.The handle spring 38 automatically returns the handle 34 to theretracted position (shown in FIG. 9). The user can now stand on theplatform 42 to access the bed box 23 over the side walls 21.

When it is desirable to return the step assembly 20 to the stowedposition, the user pulls on the handle 34 (shown in FIG. 10). Theratchet mechanism 58 is designed to unlock the step 30 in response toover rotation of the step 30 in the first direction beyond the operativeposition. Specifically, the manipulation of the handle 34 rotates thearms 32 and the cam 62 again in the first direction such that theratchet mechanism 58 begins to release as shown in FIG. 14. The tab 72of the cam 62 engages the first arm 78 to pivot the pawl 60 such thatthe over-center spring 84 flips to urge the pawl 60 toward the unlockingposition as shown in FIG. 15. Again a click or ratchet sound willsignify the switching of conditions. The second arm 80 of the pawl 60engages and follows the curved camming surface 74. Further rotationcontinues until the second arm 80 is fully seated in the second notch 70as shown in FIG. 16 which limits rotation of the step assembly 20. Thestep assembly 20 is now in the fully released position.

The user can then allow the step assembly 20 to counter rotate, shown inFIG. 17 as arrow B, back to the stowed position. Specifically, thespring 54 rotates the shaft 48, arms 32, cam 62 and associated devicesto return the entire step assembly 20 to the stowed position. As thespring 54 counter rotates the cam 62, the tab 72 will engage the secondarm 80 to pivot the pawl 60 back toward the locking position as shown inFIG. 17. A click or ratchet sound will signify the change.

Tab 72 is positioned such that when over-center spring flips to urge thepawl 60 to the unlocking position, the cam 62 has already rotated sothat the abutment arm 78 will not re-engage the notch 68. The pawl 60engages the annular outer surface 66 of the cam 62 as shown in FIG. 18.The arms 32 and cam 62 can therefore continue to be counter rotated, asshown by arrow B in FIG. 18, until the step assembly 20 has returned tothe stowed position as shown in FIG. 19. The bumpers 46 engage themounting bracket 26 to cushion the return rotation of the step 30.

The invention has been described in an illustrative manner, and it is tobe understood that the terminology which has been used is intended to bein the nature of words of description rather than of limitation. Manymodifications and variations of the present invention are possible inlight of the above teachings. It is, therefore, to be understood thatwithin the scope of the appended claims the invention may be practicedotherwise than as specifically described.

What is claim is:
 1. A step assembly for use with a vehicle, saidassembly comprising; a mounting bracket adapted to be mounted to thevehicle, a platform pivotally secured to said mounting bracket forrotation between a stowed position and am operative position, a biasingdevice mounted between said bracket and said platform for biasing saidplatform towards said stowed position, and a ratchet mechanism mountedbetween said bracket and said platform, said ratchet mechanism lockingsaid platform in said operative position in response to rotation of saidplatform from said stowed position to said operative position andunlocking said platform in response to over rotation of said platformbeyond said operative position and thereafter allowing said platform tocounter rotate back to said stowed position, characterized by saidplatform having a pair of J-shaped arms pivotally secured to saidbracket at a tip of each of the J-shaped arms, a handle pivotallymounted to said platform and manually movable between a retractedposition and a deployed position, and a handle spring biasing saidhandle toward said retracted position, said handle extending in adirection opposite said platform when said handle is in said retractedhandle position, and said handle extending in a same general directionas said platform when said handle is in said deployed position.
 2. Anassembly as set forth in claim 1 wherein said ratchet mechanism includesa pawl, a cam and an over-center spring, said pawl operatively engagingsaid cam locking and unlocking said platform and said over-center springbiases said pawl to either a locking or unlocking condition.
 3. Anassembly as set forth in claim 2 wherein said pawl has a crescentconfiguration with first and second abutment arms, said pawl beingpivotally mounted to said bracket at a pivot point between said abutmentarms, and said cam is secured to said platform to pivot therewith androtate relative to said pawl.
 4. An assembly as set forth in claim 3wherein said cam has a circular configuration with first and secondnotches formed therein, said first and second notches separated by atab, said first arm selectively engaging said first notch when said pawlis in the locking condition during said rotation of said platformthereby limiting counter rotation thereof at said operative position,said second arm selectively engaging said second notch during said overrotation of said platform limiting over rotation thereof, and said tabswitches said pawl to the unlocking condition upon over rotation and tothe locking condition upon counter rotation.
 5. An assembly as claimedin claim 4 wherein said tab and said first notch are positioned so thatwhen the pawl switches from the unlock condition to the lock condition,the pawl is unable to become seated in the first notch.
 6. An assemblyas set forth in claim 2 wherein said mounting bracket includes a hollowtube and said J-shaped arms are connected by a shaft, said shaft journalmounted in said tube.
 7. An assembly as set forth in claim 6 furthercomprising a bumper mounted to at least one of said arms, said bumperpositioned to engage said bracket to limit counter rotation of saidplatform in said stowed position.
 8. An assembly as set forth in claim 7wherein said spring is wound about said shaft with a first end mountedto said tube and a second end mounted to said shaft.
 9. An assembly asset forth in claim 8 further including a flange fixedly secured to saidtube with said pawl mounted to said mounting flange.
 10. An assembly asset forth in claim 9 further including an exterior cover secured to saidflange and encompassing said ratchet mechanism.
 11. An assembly as setforth in claim 10 wherein said platform includes a stepping surface fora user.
 12. An assembly as set forth in claim 11 wherein each of saidarms include a flange portion for interconnecting said platform to saidarms.
 13. An assembly as set forth in claim 12 wherein said handleincludes a shaft pivotally mounting said handle to one of said arms ofsaid platform and said handle spring is wound about said handle shaft.